Indicator



March 17, 1942. H. MENELSON INDICATOR Filed Jan. 2, 1941 All"EllIIslllllllsllllllllllisll `s/s'o warf *K v :inventor Patented Mar.17, 1942 INDICATOR Hans Mendelson, Camden, N. J., assigner to RadioCorporation of America, a corporation of Dela- Ware vApplication January2, 1941, Serial No. 372,847

(Cl. 11S-124.1)

'7 Claims.

This invention relates to indicators and particularly to tuningindicators for radio apparatus.

The accurate calibration of a radio dial is a time consuming operationand is so expensive as to inhibit very close tolerances in themanufacture of table model and midget sets made by mass productionmethods. It is thus not unusual to nd the decimal indicia omitted fromthe tuning scales of such low priced receivers. In the absence of suchsubdivisions on the tuning scale the operator may experience somediiiiculty in tuning to a desired station, especially, if the stationdesired is in the more crowded portion of the tuning band.

It is accordingly an object of the present in- Vention to obviate theabove described and other disadvantages of coarsely calibrated tuningindicators.

Another object of the vpresent invention is to provide a tuningindicator comprising a main scale containing coarse indicia and anauxiliary scale containing concealed minor or decimal indicia which maybe easily set up, even by an inexperienced operator, to indicate thesetting of the more frequently dialed stations.

Another and important object of the invention is to provide a readilyreadable, simple, inexpen sive, trouble-free, tuning indicator having noloose parts vand of pleasing appearance, and one which lends itselfreadily to mass production methods.

The foregoing objects are achieved in accordance with the invention in-atuning indicator comprising a pointer and a scale-bearing surface, bythe provision of a colored stripe or marginal edge on the said surfaceand a strip of frangible material mounted adjacent and normallyconcealing said edge. The frangible strip is preferably scored (bothhorizontally and in a direction normal to the direction of extension ofthe scale) to provide a plurality of easily detachable tabs, each of asize calculated, when removed, to reveal a portion of said coloredmarginal edge of a width sufficient to provide a satisfactory indicationof a particular station setting. When the pointer travel is of standardlength ('7 inches or more) the detachable tabs are preferably of a widthcorresponding to the band Width (at present, 9 kc. in the United Statesbroadcast band) of the signals, though if the pointer travel is verysmall, (say of the order of 4 inches) the tabs and hence the revealeddiscreet portions of the colored marginal edge of the scale may besubstantially wider.

Certain preferred details of construction, to-

gether with other objects and advantages, will be apparent and theinvention itself will be best understood by reference to the followingspecification and to the accompanying drawing, wherein Figure 1 is afront plan View of a tuning indicator constructed in accordance with theprinciple of the invention, A

Figure 2 is a sectional View taken on the line 2--2 of Fig. 1,

Figure 3 is an enlarged fragmentary plan View of the scored frangiblestrip employed in the device of Figs. 1 and 2,

Figure 4 is a sectional View taken on the line 4 4 of Fig. 3,

Figure 5 is an enlarged fragmentary view of the lower part of the dialassembly shown in Fig. 2, and

Figure 6 is a fragmentary front plan view of a two band tuning indicatorwithin the invention.

In Figs. 1 to 5 inclusive, wherein like reference characters designatethe same parts in each iigure, I designates generally a transparentscalebearing surface or dial having relative widely spaced numerical orother major indicia thereon and provided along its lower marginal edgewith a preferably colored stripe 3 which extends throughout its length.The dial I may conveniently be supported in a frame or bracket 5 .on thecontrol panel I of the set and is provided adjacent to its rear surfacewith a cursor or pointer 9 which is arranged to sweep the scale whendriven by a cord I I, or by a rack or equivalent driving mechanism.Mounted in front of the colored stripe or band 3 is an opaque ordifferently colored strip I3 which normally conceals the said band andwhich may be clamped thereagainst as by means of a molding I5 which extends below the bottom edge of the dial and is secured to the frame 5as'by means of screws Il.

The opaque strip I3 which conceals the colored marginal edge 3 of thescale bearing surface I is preferably constituted of a syntheticresinous material such, for example, as vinyl acetate or otherthermoplastic or thermosetting compound which,v though semi-rigid whenlUnscored, is frangible when scored and may be easily and cleanly brokenalong the scoring.

The strip I3 is cut or it may be merely scored in a direction normal tothe direction of extension of the colored marginal edge 3, as indicatedat a (Figs. 1 and 3) and is scored lengthwise with respect to said edge,as shown at b, (Figs. 3, 4 and 5) to provide a plurality of detachabletabs c each of a size calculated, when removed, to re` veal a readilydiscernible portion of the underlying color. These tabs c may be of awidth corresponding to the band width of the discrete signals indicatedon the scale by the pointer. Thus, where the scale is designed to coverthe present U. S. broadcast band the tabs may each occupy a spacecorresponding to the distance the pointer must travel in passing betweentwo points nine kilocycles apart.

The foregoing is not to be construed as meaning that the tabs c mustnecessarily be all of the same width, since the spacing required toindicate a given frequency band may be different at different pointsalong the main scale. The tabs may, of course, be of the same size ifdesired and may be of a width suitable to indicate decimal gradations orother sub-divisions of the main scale. If desired, the exact width ofthe tabs c may be dictated by local receiving conditions or, indeed, bythe selectivity and sensitivity of the set.

When it is desired to set-up a station on the indicator, the numericalindicia on the dial aid in locating the station, although the absence ofvisible subdivisions on the scale may require additional manipulation ofthe tuning knob (not shown) to ensure accurate tuning. When the stationto be set-up is tuned in, the tabe c which is on line with the pointer,at that particular setting, may be removed as by grasping it adjacentits exposed (top) edge and urging it outwardly, as shown in Fig. 5. Itwill be observed upon close inspection of Fig. 5 that the top edge ofthe molding l5 (which clamps the mask against the colored marginal edgeof the dial l) is in register with the horizontal scoring b on the maskand thus serves as a backing or guiding edge, ensuring a clean breakalong the said scored line.

In some cases, as when the tabs are quite wide, it may be desirable tomove the mask slightly With'respect to the pointer so that the pointerwill be in register with the center of a tab rather than oi center. Tothis end, the holes through which the screws I1 extend may be elongatedin the horizontal direction, as shown in Figs. 1 and 3, whereby the maskmay be shifted without removing the said screws.

Referring to Fig. 6; in applying the invention to a two-band set, orindeed to a multi-band set, the numerical or other indicia for the mainscales I9 and 20, and the colored stripes 23 and 24 for the auxiliaryscales may be marked upon the same dial or scale bearing surface 2l. Inthe case of a two-band set, it is preferable to dispose the separatelycolored stripes 23 and 24, and the masks 33, 34 therefor, along theopposite longitudinal edges of the dial, as shown, though, if desired,one of the auxiliary scales may be positioned between the main scales.

Other modifications of the invention will suggest themselves to thoseskilled in the art. It is to be understood, therefore, that theforegoing should be interpreted as illustrative and not in a limitingsense except as required by the prior art and by the spirit of theappended claims.

What is claimed is:

1. An indicator comprising a dial having a marginal edge, a pointer forsaid dial, a mask of different color for said marginal edge, and meansfor removing selected discrete portions of said mask whereby theunmasked portions of said marginal edge constitute indicia forindicating the position of the pointer required to achieve a desireddial setting.

2. An indicator comprising a dial having a distinctively colored stripethereon, a pointer for said dial, a mask of different color for saidcolored stripe, and means for removing selected discrete portions ofsaid mask, whereby the unmasked portions of said distinctively coloredstripe constitute readily discernible indicia for indicating theposition of the pointer required to achieve a desired dial setting.

3. An indicator comprising a dial having a main scale and a coloredmarginal edge coextensive with said main scale, a mask of dierent colorfor said colored marginal edge, means for removing discrete narrowportions of said mask whereby to provide an auxiliary dial scale Whereonthe indicia comprise the discrete unmasked narrow portions of saidcolored marginal edge, and a pointer common to said main and auxiliaryscales.

4. An indicator comprising a dial having a distinctively colored stripethereon, a pointer mounted for movement along said stripe, a mask ofdifferent color mounted in front of said stripe and comprising aplurality of detachable tabs each of a size calculated, when removed, toreveal sufficient of said distinctively colored stripe to provide areference indicia for said pointer.

5. An indicator comprising a scale-bearing surface having adistinctively colored stripe thereon, a mask o f different colorconstituted of a synthetic resinous material mounted in front of saidstripe and comprising a series of detachable tabs dened by scoring whichextends parallel to and in a direction normal to said distinctivelycolored stripe, said tabs being each of a. size calculated, whenremoved, to reveal sumcient ofl said distinctively colored stripe toprovide reference indicia for said scale-bearing surface.

6. The invention as set forth in claim 5 and wherein said mask isconstituted of vinyl acetate.

7. Anindicator for radio apparatus comprising a dial having a signalband scale thereon, a pointer for said scale, said dial having a coloredmarginal edge running lengthwise of said scale, a strip of differentlycolored frangible material mounted adjacent and normally concealing saidcolored marginal edge, said frangible material being scored to provide aplurality of detachable tabs each oi a size calculated, when removed. toreveal a portion'of said colored marginal edge of a width correspondingsubstantially to the band width of the signals indicated by said pointeron said signal band scale.

HANS MENDELSON.

